Defect structure development in 14 mev neutron irradiated copper and copper dilute alloys

Copper and twelve different copper base dilute alloys (Ni, Si, Ge and Sn) are irradiated with fusion neutrons from RTNS-II at 300-723 K, up to 6 × 10²² n/m². Roles of free defects are detected by the comparison of defect structures irradiated as thin foil and those as bulk, and the analysis on defect structure in pure copper gives 10 keV as sub-cascade energy. The direct formation of vacancy clustered defects from cascade damage is enhanced by oversized solutes. Oversized solutes as well as undersized solutes enhance the formation of the interstitial type dislocation loops by reducing the interstitial mobility and the stabilizing the loop nucleus. Existance or non-existance of dislocation loop formation near a dislocation gives a good criteria of the bordering condition for the loop formation. Well grown voids are observed in pure copper at 563 K, but they are not formed in all the alloys of 2 at%.